Pressure-operated multiple-circuit switch



Sept. 2, 1930. y J MACKE Er AL PRESSURE OPERATED MULTIPLE CIRCUT SWITCH Filed March 29,. 1927 invento/os eal el /Vug H /Sehmzfy E@ W Patented Sept. 2, 1930 UNITED STATES PATENT Nori-ICE JACOB MACKE, OF BELLEVILLE, ILLINOIS, AND-'HARRY SCHMITZ, 0F WEBSTER GBDVES,

' MISSOURI PRESSURE-OBERATED MIJL'IIPL11-CIRCUIT.` SWITCH Application led March 29, 1927. Serial No. 179,328.

This invention relates to pressure gauges such as are designed to be used in connection with the lubricating systems of internal combustion engines for the purpose of determiningthe pressure in the system. The general object pf the present invention is to provide a pressure gauge'which will indicate by visual signals whether the pressure of the oil is too low, too high, or at the proper point.

A further object is to provide an oil pressure gauge having a cylinder, a piston therein and a stem, the cylinder being grounded and the stem operating in conjunction` with three or more electrical contacts arranged at different heights so that when the piston is in its lower-most position it will engage with `one of the contacts, thus energizing a light. When the pressure rises to normal, it will break its electrical engagement with the firstnamed contact and engage a second contact, thus indicating that the pressure is normal, and' when the pressure is above normal, the piston will rise suiiiciently high so as to engage with a third contact and close the circuit through a lightor other signal indicating this abnormal pressure.

Other objects will appear the following description.

Our invention is illustrated in the accompanying drawings, wherein:

Figure 1 is a vertical sectional view of our improved pressure gauge.

j Figure 2 isa transverse section on the line 2"-2 of Figure 1.

Referring to the drawings, 10 designates `a metallic cylinder having a bore 11 in the head l2 at the lower end of the cylinder, and being connected by a pipe 13 to an oil pump or other force Afeed mechanism of this character. The upper end of this cylinder is internally screw-threaded and adjustable in the upper end of the cylinder is an exteriorly screw-threaded cap 14 which is preferably hollow. Disposed Within the cylinder is a spring pressed piston 15 having any usual or in the course of suitable packing and having a stem 16 which extends out through the cap and is screwthreaded for engagement by an adjustable contact 17. This contact member 17 is metallic and is adjustable up and down upon the rod 16 and is relatively long for a purpose which will be later explained. The cap 14 is held in its adjusted position within the cylinder 10 by the set or jam nut 18.

Havingscrew-threaded engagement with the cap 14 is a fibre cap 19 which may be made of any suitable insulating material and within which the upper end of the piston rod 16 and the contact 17` operates. Extending through the top of this cap is a screwthreaded pin 20 constituting a contact and formed with a nick at its upper end whereby a screw driver may be applied thereto to adjust it. This pin is provided with the locking nut or jam nut 21 and with the binding nut 22 so as to permit the pin to be connected to a conductor. Extending through the side wall of the fibre cap 19 adjacent its lower end is the metallic lbushing 23 interiorly screw-threaded for engagement by a pin 24, this pin bearing against a rotative ball or equivalent member 25. The pin 24 is locked in adjusted position by means of the lock nut 26 and carries a binding nut. 27 whereby the pin may be connected in an electrical circuit.

Disposed approximately midway between the Contact pin 24 and the contact pin 20 is another metallic bushing 28 interiorly screwthreaded for the contact pin 29 which carries the lock nut 30 and the binding nut 31.

It will be seen that the upper contact pin 2O may be adjusted up or down and that the contact member 17 upon the piston rod may also be adjusted. This contact member 17 is relatively long in order to provide for contact with the ball 32 on the Contact pin 29 .through a relatively long period. At the same time this contact 17 is of such length that when it is in contact with the ball 25 or contact member at .the lower end of the f libre cap it will not be in contact with the ball 32 and thatvwhen it moves upward it will brealr contact With the ball 32 Just before it malres contact `with the pin 20. A spring 33 surrounds the stem i6 and bears at one end against the cap land the other end againstthe piston 155 so as to urge the piston downward.

The Contact pin 2l at thelovver end et the nbre cap is connected in circuit with a source oiE current and with a red light. lhe contact pin29 is connected in circuit with a source of current and with a White light and the pin 20 is connected in circuit With a source current with a blue light. rlrhis circuit includes the grounded cylinder l0. Thus it will be seen that when the pressure in the oil line is low the Contact l? will engage with the ball 25 and the red light will be energized, thus indicating that the oil pressure is below normal. or 'when the pressure rises, the contact l?" will engage the ball 32 and the White light will be energized. lt the pressure rises to an abnormal extent, the pin le will engage the contact pin 20 and the-blue light will be energized. Thus, an indication Will be given to the driver as to Whether the pressure in his oil line'is too lovv or too high or normal. lreferably, the contact l? Will have such a length that it will contact With the ball 32 through quite a range of pressures. nihus, for instance, the contact ll' Will stay in electrical engagement with the contact 32 under pressure trom live lbs. to thirty lbs., that is,

thirty lbs., or the gauge may be so constructed that the contact if? Will energize the white light from tive lbs. to sixty lbs. By adjusting the contact l?, any desired range be secured. is to be noted that the cap ld constitutes a pressure regulating device. By turning this cap inward, the pressure on the spring 33 is increased. By turning it from the head l2, the pressure is decreased. Thus, as the pressure is increased, greater resistance is oliiered to the inivard movement ci the piston and greater pressure oil is required in order to shiit the piston inward -from its initial position. The contact pin 2O is also adjustable in or out so as secure proper instant of contact' l etveen the entremities of the piston rod ld and this pin.

lie operation oi"- this device when a driver gets into arnachineis as iiollovvs :The nist/thing he does is to turn the ignition lrey to the engine. it this time, et course, the pressure ot oil is very slight ii"- any and, there-tore, the Contact j!" is in engagement with the contact ball 23 and as soon as the ignition circuit is opened the red light Will be displayed. The motor is then started and as soon as a slight pressure is-reached as tor instance, live lbs. ot pressure, the red light Will be cle-energized and the contact 1'? vvill reach the white light Contact 32 and the white light will be ener ima-,scr

gized. This White light will burn when the engine is running normally, but it the' 1veather is cold or if the engine is cold and must not be' raced, the oil will cause high pressure, higher than normal and the piston Will leave the White light contact and engage the contact pin 20, thus energizing the blue light and notifying the driver of danger from. high pressure and that he is not to race the motor.

Another advantage of this invention is as follows: The oil pit or chamber is ordinarily rearward of the motor and the oil pump is located in this pit. .L novT the machine goes do a long incline or hill, the oil Will run to the iront oit the motor or the oil chamber leave the oil pump so that na oil Will go through the feed pige, Which may cause the bearings to burn. Under these circumstances, the red lamp will be energized, thus notiiying the driver 01 the danger. The same thing is true if the motor springs an oil lealr or the oil gets lovv.

lt Will be noted that there is no gauge to read and that visual or other obvious signals are used to indicate dangerous or safety conditions in the oil line. This is very advantageous for it the car is traveling in trailic Where the driver must have his eyes alvvays en the road, these three or more light signals 'will be so evident that the driver cannot help but see them and thus the necessity ot closely Watching the pressure gauge is done away with. rllhese livhts are preferably installed on instrument board but obviouslyvthey may be installed in any position Where they will be obvious. With this construction, the motor does not stop or become stalled when the oil pressure drops below a certain point. @ur device simply varns the driver so, that he can run slow until he can get help and service. These devices can be installed at any place about the engine il connected on the pressure leed line so as to receive the lull pressure or the oil on the piston lnasmuch as there may he a small leakage ot oil past the piston We preferably the libre cap l@ with a drainage opening Se. course, vve do notv tvisli to be limited to the enact construction illustrated, nor to the precise arrangement oit parts as these may be varied in many ways Without departini the spirit oft the inven on as defined in the appended claims.

qLT/e claim c. pressure indicator including a cylin er having an inlet at one end and adapted to e connected to a source of pressure, an ad- 'justable cap formed at the opposite end of the cylinder, a piston rod passing through said cap, spring bearing at one end against cap and at the other end against the piston, a cap oli' insulating material operatively seto the cylinder, a plurality of contact members mounted in said cap at spaced distances, one of said contact members extend `gated in the direction of the rod, and having a length only slightly less than the distance between any two of the first-named contact I members.

2. A pressure indicator comprising a cylinder having an inlet at one end adapted to be connected to a pressure line, a piston operating within the cylinder and having a metallic,piston rod adapted to be at all times connected to a source of energy, a spring urging the piston toward the inlet opening, means for adjusting the tension of said spring, a plurality of cont-acts arranged in longitudinal series on but insulated from the cylinder, each contact being adapted to be connected in a circuit with the source of energy and a signal, an elongated, longitudinally adjustable metallic contact member carried upon the piston and adapted to succes- ,Sively engage said iirst named contacts to energize the signal and having a length nearly equal to but slightly less than the distance between said first-named contacts, and a contact member passing through the end of the cylinder and adjustable therethrough and adapted to be operatively connected in a circuit with the source of energy and a signal and to be electrically engaged by the piston, said contact member acting as an adjustable stop against which the piston strikes when itis fully forced inward.

3. A pressure indicator including a nonconductive cylinderfsection closed at one end and internally screw-threaded at the opposite end, va hollow metallic cap externally screw-threaded and engaging the cylinder section, a metallic cylinder constituting a continuation of the nonconductive cylinder and having screw-threaded engagement with'the cap whereby the cap may be adjusted into or out of the metallic cylinder, and having an inlet opening at its endremote from the cap,

means for locking the cap in its adjusted position in the metallic cylinder, a metallic piston rod passing through said cap, .a piston disposed within the last named cylinder section, a spring bearing at one end against the cap and at the other end against the. piston, a plurality of contact members mounted in said Anonconductive cylinder section and spaced from each other a distance slightly greater than the length of the piston distances, one of said contact members extending through the end of the nonconductive cylinder section and being longitudinally adi justable therein an'd adapted to be engaged by the piston rod when the piston rod has been forced fully inward, the metallic cylinder section and the several contacts on the nonconductive cylinder section being adapted to be each connected in circuit to the source of energy and the signal.

4. A pressure indicator including a cylinder, a piston operating therein, the cylinder having an inlet opening, a spring urging the piston 'toward the inlet opening, an electrical contact carried by the piston and moving therewith, the contact being elongated in the direction of the length of the piston and being rounded at its ends, and a contact disposed in the path of movement of the piston carried contact and adapted to be engaged thereby as the piston moves to a predetermined position and comprising asocket extending through the wall of the cylinder and having a binding screw exterior to the wall, a metallic spring disposed within the socket, and a metallic ball disposed within the socket and urged by the spring outward into the path of movement of the piston carried contact.

5. A pressure indicator of the character described including a non-conductive cylinder section closed at one end and internally screwthreaded at the opposite end, a hollow metallic cap externally screw-threaded for engagement with the cylinder section, a metallic cylinder constituting a continuation of the non-conductive cylinder and having screw- I ton' rod passing through the cap, a piston `disposed within the last named cylinder section, a spring bearing at one end'against the cap and at its other end against the piston, the cap being counter-bored to receive the adjacent end of the spring, a longitudinally elongated contact member disposed withinV the non-conductive cylinder and mounted on the piston rod for longitudinal adjustment thereon, and a plurality of contact members extending through the walls of said non-conductive cylinder section and spaced from each other a distance nearly that of the contact member carried upon the piston rod, the metallic cylinder section and the several contacts on the non-conductivecylinder section being adapted to be each connected in circuit to the source of energy and a signal.

6. A pressure indicator 'including a cylinder having an inletat one end adapted to be connected to a pressure line, a piston operatingwithin the cylinder/and having a piston rod, means urging the piston toward 'the inlet opening, an insulating member mounted upon the cylinder and into which the piston rod passes, the insulating member having a drainage opening, a. plurality of contaots arranged in series on the insulating member and each adapted to be connected to a, source 02E energy and o, signal, and a, Contact member carried upon the 'piston rod and adapted to successively engage said. firstnamed contacts and energize the signal, the Contact member being elongated.

n testimony whereof We hereunto afx our signatures.

' JACOB MACKIE).

HARRY SCHMITZ. 

